1. Field
Apparatuses and methods consistent with exemplary embodiments relate to an apparatus and method for processing an audio signal, and more particularly, to an audio signal processing apparatus which controls a gain of an input signal and an audio signal processing method thereof.
2. Description of the Related Art
As the utilization of a television (TV), a home theater, a tablet personal computer (PC), a mobile phone and the like has increased along with the consumption of digital media on those devices, a demand for more vivid sound in movie, music, etc. has been gradually increased.
For example, a lower frequency range includes a component that makes a listener feel a sensation of beating, and it is therefore possible to reinforce a rhythmical sense a listener feels by controlling a gain corresponding to a dynamic characteristic of a lower range sound.
FIG. 1 shows an example of a sound width expanding apparatus (hereinafter, referred to as an ‘expander’) that reinforces the lower range sound in accordance with the related art.
As shown in FIG. 1, the expander for reinforcing the lower range sound adjusts an output level by monitoring a level of an input signal with respect to a preset threshold and generating a gain control signal. Accordingly, if the level of the whole input signals gets out of a range detectable by the preset threshold, no operation may be performed. Further, the output level is adjusted as much as a preset expanding ratio, there may be a misoperation where the adjustment of the level is too high or too low.
For this reason, the related art expander for reinforcing the lower range sound has been mostly operated in such a manner that an acoustic expert directly sets up a gain value in accordance with characteristics of the input sound. Thus, it is general that the related art expander is used when creating music, that is, at sound mixing.
An extreme low frequency signal having no effect on tone color may be added to a sound signal so as to reinforce the sensation of the lower range in accordance with the related art.
FIG. 2 shows an example of a sound width expanding apparatus that adds the extreme low frequency signal in accordance with the related art.
As shown in FIG. 2, a related art expander for adding the extreme low frequency signal is realized in such a manner that a proper amount of extreme low frequency signal is added to a necessary section under an expert's precise control during the sound mixing.
Accordingly, most of sound mixing for reinforcing the lower range sound or adding the extreme low frequency signal is manually performed by an acoustic expert because it often needs experiences and techniques. Further, it may be is difficult for an ordinary listener to apply any manual adding to completely mixed content and apply any manual adding to practical appreciation such as a movie or music.